Mechanically Stabilized Earth (MSE) Wall Backfill Water Infiltration

For Mechanically Stabilized Earth (MSE) retaining walls located along rivers and streams, American Association of State Highway and Transportation Officials (AASHTO) specifications require a differential hydrostatic pressure equal to 3.0 feet of water be applied to the wall system (see AASHTO section 11.10.10.3). The following is provided in the comment section of the AASHTO specifications: ‘Situations where the wall is influenced by tide or river fluctuations may require that the wall be designed for rapid drawdown conditions, which could result in differential hydrostatic pressures considerably greater than 3.0 feet, or alternatively rapidly draining backfill material such as shot rock or open graded gravel can be used as backfill. Backfill material meeting the graduation requirements in AASHTO LRFD Bridge Construction Specifications for MSE structure backfill is not considered to be rapid draining’ Since AASHTO considers the MSE structure backfill to not be rapid draining they would also consider them to not be rapid infiltrating. Therefore, the goal of the research would be to evaluate how water infiltrates into MSE structure backfill and develop a model to document this condition. For example, in a situation where the hydraulic design for a 10 foot high MSE wall structure indicates that the water level will consistently rise for one hour to a height of 5 feet below the top of the wall, then remain there for 4 hours, then will consistently fall for one hour to a level below the bottom of the wall, what will the line between saturated and partially saturated soils (wetting front) within the MSE structure backfill look like and what will the corresponding internal and external lateral forces be on the MSE wall. The intended outcome of this study is to meet the following objectives: (1) Conduct a literature search to determine what research has been performed to evaluate infiltration into MSE structure backfill. (2) Develop a laboratory testing program to evaluate the infiltration into MSE structure backfill. (3) Based on the laboratory testing program, develop a model that can predict the line between saturated and partially saturated soils (wetting front) and internal and external lateral earth pressures.

Language

  • English

Project

  • Status: Active
  • Funding: $150000
  • Contract Numbers:

    0092-18-07

  • Sponsor Organizations:

    Wisconsin Department of Transportation

    4802 Sheboygan Avenue
    Madison, WI  United States  53707
  • Performing Organizations:

    University of Wisconsin, Madison

    Department of Civil and Environmental Engineering
    1415 Engineering Drive
    Madison, WI  United States  53706
  • Principal Investigators:

    Likos, William

  • Start Date: 20171117
  • Expected Completion Date: 20191117
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01668935
  • Record Type: Research project
  • Source Agency: Wisconsin Department of Transportation
  • Contract Numbers: 0092-18-07
  • Files: RiP, STATEDOT
  • Created Date: Jan 10 2017 12:11PM